Language Is Key To Making Machine That Can 'Think'

The fact that computers can't match the linguistic skills of a bright 5- year-old has long been a source of good computer jokes.

In the early days, the standard joke was about the computer that translated "the spirit is willing, but the flesh is weak" into "the wine is good, but the meat is rotten."

These days it's about the robot given a can of paint and told to paint the porch. "All done," the computerized machine responds after returning in an hour. "But that's not a Porsche, it's a BMW."

Artificial intelligence critics like Hubert and Stuart Dreyfus of the University of California at Berkeley believe full language understanding is beyond a computer's conceivable capabilities. Understanding the spoken word, for example, presents difficult programming problems.

"It isn't easy to wreck a nice beach," read aloud, might sound like a way of consoling a computer who doesn't hear too well. (It isn't easy to recognize speech). Telling the difference between "I scream" and "ice cream" is easier for people than for computers.

A similar problem is duplicating the cocktail effect: out of the buzz ofconversation, clanging glasses and other noise, a human can hear the mention of his or her name and immediately focus on that conversation to the exclusion of everything else.

But despite the difficulties, researchers at companies including IBM, AT& T, Texas Instruments and many smaller firms are making extraordinary progress on the language problem. Already some systems can "take dictation" if the speaker pauses between words and uses a limited vocabulary. The limit of accuracy is now about 95 percent (the computer can correctly type about 95 words out of 100). In systems where the vocabulary is highly limited and specialized (such as when a pilot issues commands in a cockpit), accuracy climbs to 98 percent.

Progress also has been rapid in the area of understanding written language. Computer translation is at least useful now, if not perfect: An ITT Corp. translating system works at about 60 to 70 percent accuracy, and then a human expert takes over to polish up the translation.

While a skillful human translator can translate 250 to 500 words per hour, with the computer's help, that output can be doubled.

Such systems don't really understand what they're doing, though. At Carnegie-Mellon University in Pittsburgh, efforts are under way to produce a system that understands the meaning and produces a usable translation without human help.

First efforts will be in restricted fields, like medicine (a patient who doesn't speak English could tell the computer the symptoms and the computer would tell the doctor) or weather information, helping meteorologists in making international forecasts.

"I think we're making quite rapid progress," said Herbert Simon, professor of computer science and psychology at Carnegie-Mellon. Further advances in understanding language, he said, will come in programming computers to understand the meaning behind the words. Just as a human translator must understand the subject matter to prepare an accurate translation, computers must be given knowledge and context to understand human language.

An essential part of progress in these areas is improving a computer's sensory capabilities - especially sight and hearing. Crude computer vision systems have been developed and artificial ears and even an artificial nose have been devised. But they are from from perfected.

"It's clear that the hardest job we've tackled so far and the one in which we've made the slowest progress is in simulating the work of the sense organs," said Simon.

In other problem areas, such as making computers that exhibit common sense and exercise sound judgment, researchers today are taking the first tentative steps. Simon is confident these efforts will ultimately succeed.

"I think the sky's the limit," he said.

But if the research succeeds in solving today's problems, he acknowledges, the idea of intelligent machines may raise other concerns.

"AI does arouse anxiety in a lot of people," he said. "It's something about the image of man, challenging our uniqueness. There've been such challenges before. Copernicus certainly challenged our uniqueness when he took us out of the center of the universe. Darwin challenged it . . .

"I think this again does challenge our human uniqueness. We can respond to that in a variety of ways. I prefer to respond to it by saying why are we so uptight about uniqueness anyway? Do I have to get my sense of worth by being different from other things and other people?"

In fact, he suggested, the loss of uniqueness might open the way to a more harmonious existence of people with their environment.

"We are beginning to understandourselves as a part of nature, as subject to natural law," he said. "We are going to survive and thrive if we learn how to live in harmony with nature and not by devoting all of our efforts to distancing ourselves from the world we live in.

"We'd better understand how to survive as part of the system and not say, 'Well, here we are and there it is and we're the master of it all.' I don't think we're the master of anything."